STS-92
Report # 08
Sunday, October 15, 2000 ñ 6:30 a.m. CD
Two of Discoveryís astronauts will continue outfitting the most recent
addition to the International Space Station during a scheduled 6 W*-hour
space walk today.
Mission Specialists Bill McArthur and Leroy Chiao will connect two sets of
cables to provide power to heaters and conduits located on the Z1 truss,
relocate two communication antenna assemblies and install a toolbox for
use during future on-orbit construction. The space walk is scheduled to
begin about 9:45 this morning. Japanese Astronaut Koichi Wakata will once
again be at the controls of the Shuttleís robotic arm, using it to move
the two astronauts around Discoveryís payload bay and the Space Station.
Chiao, designated EV1 and recognizable by the red bands on the legs of his
space suit, and McArthur, designated EV2 in a solid white suit, will
devote the first hour of their space walk to set-up activities in
Discoveryís payload bay, deploying tools and EVA aids including foot
restraints and tethers. With that complete, the first task will be to
connect the first six umbilical cables between Unity and the truss
structure. To ensure that the connectors the astronauts will be working
with are not ìhot,î International Space Station controllers in Houston and
Moscow will alternately power down two Russian-to-American Conversion
Units, called RACUs. They provide power to some of the systems in the
Unity module including the early communication system and some cabin fans.
RACU 5 will be powered down to support the first cable installation and
reactivated before the power down of RACU 6, ensuring that the Unity
module will not be without power during the space walk activities. !
A second set of four umbilical power cables will be connected later in
the space walk once RACU 5 has been repowered, and RACU 6 deactivated.
Following the first cable installation task, McArthur and Chiao will
remove the S-band Antenna Subassembly (SASA) from its launch position on
the Z1 truss and place it in a temporary location until it is moved and
activated during the STS-97 mission in late November. The SASA is launched
in the position where two power conditioning systems ñ called DDCU-HPs ñ
will be installed during their space walk on Tuesday. McArthur and Chiao
will then turn their attention to installing the Space to Ground Antenna
(SGANT) deploying its antenna dish. The antenna dish will be removed from
its launch location on the Z1 truss with Chiao standing on the robotic arm
as McArthur unbolts the dish assembly. Because of thermal limitations,
the antenna dish needs to be attached to the boom assembly within an hour
after being removed from its launch location.
McArthur and Chiao also will relocate a tool stowage box, located on the
support structure for PMA-3 in Discoveryís payload bay, for use during
future on-orbit construction activities before concluding their space walk
and climbing back into Discoveryís airlock.
Throughout the EVA, the second team of spacewalkers on this flight, Jeff
Wisoff and Mike Lopez-Alegria, will act as in-cabin choreographers
providing guidance and assistance to McArthur and Chiao and back-up
support to robot arm operator Wakata.
Following the conclusion of the space walk, McArthur, Chiao, Wisoff and
Lopez-Alegria will resize the spacesuits, recharging batteries and
preparing them for the second of four consecutive days of EVAs to expand
the International Space Station.
The next Mission Control Center status report will be issued at 7 p.m. CDT
or as events warrant.